Lucky you leaving on Monday potter!
I would take casual lightweight clothes, can be very humid and sticky in the evenings.
Personally I have no probs with the mozzies, but my husband......... thats a different story!
So if you tend to be bitten it would be advisable to cover up after dark, otherwise dont bother. I wear vest tops and skirts with my arms and legs showing, I do cover exposed parts with mozzie repelant mind you...... be sure to take some with you
As Gemma said, flat comfy shoes are a must in Goa due to the poor roads and bumpy paths....... the ground is dusty and canvas shoes will get stained(a nice orangey brown colour!), so i take flip flops and a pair of old trainers.
Hope this helps.
Go with an open mind and you will have a ball!